Essential reading if you belong to a project on FamilyTreeDNA, or are considering doing so:
Roberta Estes blog about the privacy changes back in May and the recent update in August:
https://dna-explained.com/2018/08/09/family-tree-dna-group-project-privacy-levels/
Bottom line, the default privacy setting of Limited is very much more sensible than that implemented in May.
As Roberta says, you join projects to collaborate, so the setting that allows that to happen is the best option!